//GLSL
varying vec4 v_position;

void main()
{
        float depth = v_position.z / v_position.w ;
        depth = depth * 0.5 + 0.5;			//Don't forget to move away from unit cube ([-1,1]) to [0,1] coordinate system

       // float moment1 = depth;
       // float moment2 = depth * depth;

        // Adjusting moments (this is sort of bias per pixel) using partial derivative
        //float dx = dFdx(depth);
        //float dy = dFdy(depth);
       // moment2 += 0.25*(dx*dx+dy*dy) ;

       float d = 0;
       gl_FragColor = vec4(d, d, d, 1.0); ;//vec4( moment1,moment2, 0.0, 0.0 );
}
	